[PLUG] nVidia settings errors

[Dick Steffens]

I have an nVidia card in the computer in the living room with its HDMI 
port connected to the TV. When I boot up the machine the primary screen 
is the TV. But with the underscan issue (described some years ago), it 
is hard to click on the controls at the top of the screen. I've tried 
changing the default screen with nvidia-settings, but the changes never 
take. This morning I remembered  that I'm supposed to run 
nvidia-settings with sudo. The OS is xubuntu 18.04. I get this message 
when I run nvidia-settings:

--------------------------------
rsteff at ENU-1:~/Desktop$ sudo nvidia-settings
[sudo] password for rsteff:

(nvidia-settings:4037): GLib-GObject-CRITICAL **: 08:47:49.103: 
g_object_unref: assertion 'G_IS_OBJECT (object)' failed

(nvidia-settings:4037): IBUS-WARNING **: 08:47:49.138: The owner of 
/home/rsteff/.config/ibus/bus is not root!

ERROR: nvidia-settings could not find the registry key file. This file 
should
        have been installed along with this driver at either
/usr/share/nvidia/nvidia-application-profiles-340.108-key-documentation
        or 
/usr/share/nvidia/nvidia-application-profiles-key-documentation. The
        application profiles will continue to work, but values cannot be
        prepopulated or validated, and will not be listed in the help text.
        Please see the README for possible values and descriptions.


** (nvidia-settings:4037): WARNING **: 08:47:49.297: PRIME: Failed to 
execute child process “/usr/bin/prime-supported” (No such file or directory)
** Message: 08:47:49.298: PRIME: is it supported? no
Package xorg-server was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-server.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-server' found
--------------------------------

I tried searching for the first couple of errors the responses might 
just as well have been in Greek.

One of the hits I got later on recommended running nvidia-settings using 
gksudo. This, I learned, has been deprecated, and neither of the 
recommended alternatives worked. One was to us admin:// nvidia-settings. 
That returned admin://: no such file or directory. The other was to use 
pkexec nvidia-settings. That returned "Unable to init server: Coundd not 
connect: Connection refuse. Error: The control display is undefined; 
please run '/usr/bin/nvidia-settings --help' for usage information."

A clue stick would be appreciated.

-- 
Regards,

Dick Steffens